Fig 4. Planar polarity during ovule integument growth is compromised in hap13-1.

(A-B) Semi-thin sections of wild-type (A) or hap13-1 ovules (B) at developmental stage 2-I, 2-III, 3-I, or 3-V. ac, archesporial cell; dm, degenerating megaspore; fm, functional megaspore. Yellow-shaded areas are cells of inner integuments. Blue-shaded areas are cells of outer integuments. Pink-shaded areas indicate the embryo sacs. (C-D) Cell number and size of wild-type (C) or hap13-1 (D) outer integuments. Each column represents one stage 3-V ovule; the number of cubes in each column indicates the number of countable outer integument cells in a stage 3-V ovule; green cubes indicate small cells (area between 0.2 and 0.4, a.u.) while yellow cubes indicate large cells (are between 0.4 and 1, a.u.). (E-F) CLSMs of wild-type (E) or hap13-1 ovules (F) at stage 3-II, 3-III, or 3-IV. Ovules were stained with PI and mid-optical sections were shown. Because some hap13-1 ovules were completely avoid of embryo sac patterning and thus impossible to determine developmental stages, only hap13-1 ovules with visible nuclei are shown in (F). cn, chalazal nucleus; fu, funiculus; ii, inner integument; oi, outer integument; mn, micropylar nucleus. Bars = 10 μm.